From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD322C47423 for ; Tue, 29 Sep 2020 12:44:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CA6320725 for ; Tue, 29 Sep 2020 12:44:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601383499; bh=sSXBrKnfvFxp02IRBIEvBTV7hKCLv23aDEhg+nMWbII=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tG4SeOMz44aJcuh1a2Fp5VQJWmJkVSRj5+tIsRvhn++iaVnNQnBtME2qjuKto4CYS 0xUkV1UpwZETJMPCQ0sWzyTOiggLy7MrRMSc1UgW3H+6GMQMZUeJc2jYCF7s6sbgx4 +vwsDD1iH9UHIYW4R0elCxRTaL7uHyEf1g/W1Hbk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387514AbgI2Mo5 (ORCPT ); Tue, 29 Sep 2020 08:44:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:46504 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728973AbgI2LHw (ORCPT ); Tue, 29 Sep 2020 07:07:52 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4728C21D46; Tue, 29 Sep 2020 11:07:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377672; bh=sSXBrKnfvFxp02IRBIEvBTV7hKCLv23aDEhg+nMWbII=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EXniN1n8wDnAhVCG5jFAxjrNL0LIDLz1xOQnsrj9bjwYU1o5dPuxeU4mH/dG1cuDT nnJheGSjIq4gX/BuOnztawmfr1v3P3yIZTQ82ZjNh2FW02lNpsFLhyP4D3x7/5t7h7 MVjz+D50Uc0onJP47iNhjKsNhqvywWJNTTUKvNYU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Perches , Dan Carpenter , Julia Lawall , Thomas Gleixner , Kees Cook , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.9 030/121] kernel/sys.c: avoid copying possible padding bytes in copy_to_user Date: Tue, 29 Sep 2020 12:59:34 +0200 Message-Id: <20200929105931.671689510@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105930.172747117@linuxfoundation.org> References: <20200929105930.172747117@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Joe Perches [ Upstream commit 5e1aada08cd19ea652b2d32a250501d09b02ff2e ] Initialization is not guaranteed to zero padding bytes so use an explicit memset instead to avoid leaking any kernel content in any possible padding bytes. Link: http://lkml.kernel.org/r/dfa331c00881d61c8ee51577a082d8bebd61805c.camel@perches.com Signed-off-by: Joe Perches Cc: Dan Carpenter Cc: Julia Lawall Cc: Thomas Gleixner Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- kernel/sys.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sys.c b/kernel/sys.c index 157277cbf83aa..546cdc911dad4 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1183,11 +1183,13 @@ SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) { - struct oldold_utsname tmp = {}; + struct oldold_utsname tmp; if (!name) return -EFAULT; + memset(&tmp, 0, sizeof(tmp)); + down_read(&uts_sem); memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); -- 2.25.1